1. Field of the Invention
This invention relates to data copying and more particularly relates to facilitating copy protection on an electronic storage device.
2. Description of the Related Art
Data is copied for a variety of reasons. For example, a user may want to make a backup copy of data. Additionally, the user may want to move the data to make it accessible to a certain application program or network area. Different copying technologies, for example, point-in-time, synchronous continuous, asynchronous continuous, and so forth, exist in order to facilitate different copying needs.
Within a storage area network (SAN), copy functions in storage controllers allow a user to invoke a copy of one volume onto another volume. The volume from which data is copied may be referred to as the source volume. The volume onto which the copied data is written may be referred to as the destination volume or target volume. Volumes also may be discussed in terms of electronic storage devices, since a logical volume may be stored on one or more physical storage devices. When data from a source volume is copied to a target volume, the data that was previously on the target volume is overwritten by the newly copied data. When a user incorrectly specifies a target volume, valuable data on the target volume may be accidentally or unknowingly lost due to such overwriting.
Conventional copying technologies in storage sub-systems allow any volume to be selected as a target volume in a copy operation. Some exceptions apply, but they are typically limited to volumes that are in use or otherwise unavailable to participate in the copy operation. Unfortunately, accidental designation of the destination volume can cause a substantial loss of valuable data. For example, if a user means to copy data from volume A to volume B, but accidentally designates volume C as the destination volume, there may be no way to prevent the operation of copying data from volume A to volume C. As a result, the data from volume C may be lost, even though the designation of volume C as a target volume may have been incorrect and accidental.
The potential for copying mishaps using conventional techniques is complicated by the size and complexity of many SANs and storage sub-systems. A SAN system having ten storage sub-systems may have hundreds, even thousands, of volumes distributed among the storage sub-systems within the SAN system. It may be extremely difficult to track all of the illegal copying operations that may be attempted among the various storage sub-systems and volumes. Additionally, the difficulty may drastically increase as the storage sub-systems and volumes are dynamically used, replaced, and reassigned within the SAN system, thereby, requiring frequent and complicated synchronization.
From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method to facilitate copy protection. Beneficially, such an apparatus, system, and method would allow a user to protect a selected destination device against accidental or otherwise detrimental copying. The apparatus, system, and method also may beneficially eliminate the need for a complex and centralized database to describe all of the potentially illegal copy operations that may be attempted with a SAN system.